Potty Accident Question

We have a 16 week old puppy. She does great during daylight hours, rarely has an accident and goes out to potty every couple of hours. However, it seems as soon as the sun goes down she needs to go out every 15-30 minutes and if we don’t take her out that often she will pee in the house. She has no accidents in her crate at night. This is just from about 5pm until bedtime, every night. We have never had this issue in the past with previous dogs and aren’t sure what to do, how to fix it, and why this is happening.